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From: Joerg on 18 Jul 2010 16:42 krw(a)att.bizzzzzzzzzzzz wrote: > On Sun, 18 Jul 2010 09:52:00 -0700, Joerg <invalid(a)invalid.invalid> wrote: > >> krw(a)att.bizzzzzzzzzzzz wrote: >>> On Sat, 17 Jul 2010 17:21:23 -0700, Joerg <invalid(a)invalid.invalid> wrote: >>> >>>> krw(a)att.bizzzzzzzzzzzz wrote: >>>>> On Sat, 17 Jul 2010 15:56:12 -0700, Joerg <invalid(a)invalid.invalid> wrote: >>>>> >>>>>> krw(a)att.bizzzzzzzzzzzz wrote: >>>>>>> On Sat, 17 Jul 2010 09:38:50 -0700, Joerg <invalid(a)invalid.invalid> wrote: >>>>>>> >>>>>>>> krw(a)att.bizzzzzzzzzzzz wrote: >>>>>>>>> On Sat, 17 Jul 2010 09:11:49 -0700, Joerg <invalid(a)invalid.invalid> wrote: >>>>>>>>> >>>>>>>>>> krw(a)att.bizzzzzzzzzzzz wrote: >>>>>>>>>>> On Sat, 17 Jul 2010 06:33:23 -0700, Joerg <invalid(a)invalid.invalid> wrote: >>>>>>>>>>> >>>>>>>>>>>> Frank Buss wrote: >>>>>>>>>>>>> Joerg wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> I believe Newark carries them. >>>>>>>>>>>>> Digikey has it, too. Search for "keystone test points" and you'll get a >>>>>>>>>>>>> nice selection for diameter, color etc. Looks like it is popular, because >>>>>>>>>>>>> some types are available in container quantities :-) >>>>>>>>>>>>> >>>>>>>>>>>>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=5002K-ND >>>>>>>>>>>>> >>>>>>>>>>>> Thanks, I didn't know they carried these. Unfortunately such test points >>>>>>>>>>>> are comparatively large, for 0.040" holes and similar. >>>>>>>>>>> Come on Joerg. They're only three for ten bucks. You can afford them! >>>>>>>>>>> >>>>>>>>>>> <yikes!> BTW, we use something similar for less than $.10 each. ...and those >>>>>>>>>>> are usually deleted when production settles down. >>>>>>>>>> I didn't say I can't afford them :-) >>>>>>>>> ;-) >>>>>>>>> >>>>>>>>>> They are just a bit large for modern SMT layouts. Technologically a bit >>>>>>>>>> long in the tooth. >>>>>>>>> We use them on power supplies and a couple of communications lines (RS-422). >>>>>>>>> They're useful for scope grounds. >>>>>>>>> >>>>>>>>> There once were connectors that would accept a scope tip. Has anyone seen >>>>>>>>> those recently? They were *expensive* but for test jigs they would be useful. >>>>>>>> Not recently. I often use needles, the ones that come with higher end >>>>>>>> shirts. You know, where Murphy says that you'll always forget one when >>>>>>>> trying it on and ... OUCH. Many can be soldered to (not all) and then >>>>>>>> occasionally I use a rubber band to tug a bit on the cable or the needle >>>>>>>> so it won't fly out. >>>>>>> You mean "pins". Needles have a slot for the thread. ;-) >>>>>>> >>>>>> Sorry, yes, pins. As you can see it's my wife who does all the sewing >>>>>> around here :-) >>>>> You think I do? There is a reason SWMBO, MBO. ;-) >>>>> >>>> But tonight I'm doing the cookin', standing near the charcoal Weber at 100F. >>> She left you outside in that condition? >>> >> As long as there's food that's ok :-) > > Man does not live by food alone. ;-) > Well, ok, food plus beverages then :-) [...] >>>> Different here. We rarely run the A/C so I wear short and T-shirts. The >>>> office often hovers around 90F. When doing heavy-duty SPICE a lot more. >>> I wear them year around. AC or not. I don't own any others. >>> >> Wow. I'd be drenched in sweat and it would not be a pretty picture. > > Only when I'm working outside, or in the attic. The attic work likely won't > start again until at least September. I thought I might get a break today and > work out there, but nope (91F w/50% humidity and sunny). It's like working in > the rain. You can only get so wet. ;-) > That's what one guy thought. Until the whole deck gave way and turned itself into a raft. He lucked out and got off, somehow, but the deck was later found a few miles downstream. >>>>>> It does make sense to buy quality stuff. Cheap shirts can look bad after >>>>>> just a dozen washes while good ones last many years. >>>>> Yes, but you don't have to spend a lot of money on them. >>>>> >>>> I'd rather have stuff that lasts. >>> Same shirts, different day. >>> >>>>>> But hey, I knew a guy who had more money that Uncle Scrooge, was >>>>>> chauffeured around in a Bentley, yet he usually ate herring and >>>>>> potatoes. Now with food, we sometimes splurge. Same with beer, you won't >>>>>> find any cheap ones here. >>>>> ...but you do go cheap on electronics. ;-) >>>>> >>>> Yes, there's always a cost calculator running inside my brain. Even when >>>> working on hi-rel stuff where cost really doesn't matter, it simply >>>> won't turn off. Once a client asked me what the electronics would cost, >>>> more casually. "45 bucks" ... some jaws dropped ... "We can't even buy a >>>> decent wrench for that, heck, our coffee maker cost more". >>> We're on a cost kick now. The owner decided that it's his money. >>> Unfortunately, a lot of the decisions were made long ago and aren't easy or >>> cheap to change now. It's tough when the rules change after the game is in >>> play. >>> >> Mostly that will result in a complete redesign. That is when the NRE >> that entails must be factored in, to see how fast the effort truly >> amortizes. Anything north of four years is generally frowned upon. > > Yep. I'm doing a redesign now, but at least on this pass the ground rules > state that no firmware can be changed. That alone cuts the possibilities some > 80% (I've already done the design, including firmware changes). The real > bigies would hit the case, though. There is well into six figures in the > molds so there is no way that's going to pay. > That would put enclosure changes off-limits, unless you make a bazillion of these per year. I've often run into this "no SW change" or "no firmware change" requirement and never really understood it. There are nowadays so many trick you can play in firmware that save beaucoup bucks because whole chunks of hardware could simply vanish. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: krw on 18 Jul 2010 16:58 On Sun, 18 Jul 2010 13:42:04 -0700, Joerg <invalid(a)invalid.invalid> wrote: >krw(a)att.bizzzzzzzzzzzz wrote: >> On Sun, 18 Jul 2010 09:52:00 -0700, Joerg <invalid(a)invalid.invalid> wrote: >> >>> krw(a)att.bizzzzzzzzzzzz wrote: >>>> On Sat, 17 Jul 2010 17:21:23 -0700, Joerg <invalid(a)invalid.invalid> wrote: >>>> <snip> >>>>> Different here. We rarely run the A/C so I wear short and T-shirts. The >>>>> office often hovers around 90F. When doing heavy-duty SPICE a lot more. >>>> I wear them year around. AC or not. I don't own any others. >>>> >>> Wow. I'd be drenched in sweat and it would not be a pretty picture. >> >> Only when I'm working outside, or in the attic. The attic work likely won't >> start again until at least September. I thought I might get a break today and >> work out there, but nope (91F w/50% humidity and sunny). It's like working in >> the rain. You can only get so wet. ;-) >> > >That's what one guy thought. Until the whole deck gave way and turned >itself into a raft. He lucked out and got off, somehow, but the deck was >later found a few miles downstream. Wow! That *is* a perspiration problem. <snip> >>> Mostly that will result in a complete redesign. That is when the NRE >>> that entails must be factored in, to see how fast the effort truly >>> amortizes. Anything north of four years is generally frowned upon. >> >> Yep. I'm doing a redesign now, but at least on this pass the ground rules >> state that no firmware can be changed. That alone cuts the possibilities some >> 80% (I've already done the design, including firmware changes). The real >> bigies would hit the case, though. There is well into six figures in the >> molds so there is no way that's going to pay. >> > >That would put enclosure changes off-limits, unless you make a bazillion >of these per year. I've often run into this "no SW change" or "no >firmware change" requirement and never really understood it. There are >nowadays so many trick you can play in firmware that save beaucoup bucks >because whole chunks of hardware could simply vanish. Sure. The issue is two-fold, really. First, the thing works. A good chunk of the possible savings is a newer DSP (savings of $6-7 per), but they had so much trouble with TI getting this one working that the owner is afraid of touching another unknown. I can save another $30-$40 pretty easily, but at least the device drivers would have to change. I don't know how well they've isolated these from the application, either. The other issue is that there are other projects where the firmware engineers' time might be better spent. So far there hasn't been any (time), so... I've gone through so many cost scenarios on this product that I'd rather do another project too, but whatever...
From: Joel Koltner on 18 Jul 2010 17:26 krw(a)att.bizzzzzzzzzzzz wrote: > Sure. The issue is two-fold, really. First, the thing works. A > good chunk of the possible savings is a newer DSP (savings of $6-7 > per), but they had so much trouble with TI getting this one working > that the owner is afraid of touching another unknown. I've often heard that the Analog Devices SHARC DSPs are rather "friendlier" and work better (in terms of the actual behavior relative to what the data sheet claims)... have anyone there who has the time and inclination to do a bit of a skunkworks project? We're sticking with TI DSPs as well for the moment, though -- not enough spare people/time to be contemplating a change right now. ---Joel
From: krw on 18 Jul 2010 17:43 On Sun, 18 Jul 2010 14:26:45 -0700, "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote: >krw(a)att.bizzzzzzzzzzzz wrote: >> Sure. The issue is two-fold, really. First, the thing works. A >> good chunk of the possible savings is a newer DSP (savings of $6-7 >> per), but they had so much trouble with TI getting this one working >> that the owner is afraid of touching another unknown. > >I've often heard that the Analog Devices SHARC DSPs are rather "friendlier" >and work better (in terms of the actual behavior relative to what the data >sheet claims)... have anyone there who has the time and inclination to do a >bit of a skunkworks project? Nope. Not at all. They're stressed just getting the scheduled product changes done[*]. AIUI, the runner-up was the BlackFin (the guys still wear their blackfin T-shirts when the TI guys show up). A complete G729 package wasn't available for it. [*] We have a new manager, who asked me if I wanted to help out with the firmware. "Nope, I don't know how to spell 'C'. If you want it done in assembler or VHDL, fine." Besides, I have Xenocryptophobia. >We're sticking with TI DSPs as well for the moment, though -- not enough spare >people/time to be contemplating a change right now. As long as you have a competent logic designer on hand who isn't afraid of an FPGA, I wouldn't worry about it. I could have easily saved them two and maybe three years in development on this thing. ...and a lot of grief since.
From: Joel Koltner on 18 Jul 2010 18:00
krw(a)att.bizzzzzzzzzzzz wrote: >> ... have anyone there who has >> the time and inclination to do a bit of a skunkworks project? > Nope. Not at all. They're stressed just getting the scheduled > product changes done[*]. AIUI, the runner-up was the BlackFin (the > guys still wear their blackfin T-shirts when the TI guys show up). A > complete G729 package wasn't available for it. Long-term you might think about rolling your own CoDec? G.729 does seem to be pretty good, but it still has more latency than some people seem to prefer. Probably the reason why a lot of wireless mics are still using plain old analog FM? (The unfortunate downside though is that it's rather difficult to cook up a good CoDec without stepping on someone's patented IP in the process, and a lot of the IP owners aren't interested in talking with you if you're only looking for, e.g., hundreds or thousands of licenses per year.) I like Wikipedia's description of G.729 annex B: "If transmission is stopped, and the link goes quiet because of no speech, the receiving side may assume that the link has been cut. By inserting comfort noise, analog hiss is simulated digitally during silence to assure the receiver that the link is active and operational." "Comfort noise" -- that's great! :-) > [*] We have a new manager, who asked me if I wanted to help out with > the firmware. "Nope, I don't know how to spell 'C'. If you want it > done in assembler or VHDL, fine." Besides, I have Xenocryptophobia. I generally only volunteer to do firmware when it's a small enough project that I can do the entire thing myself -- e.g., a smart battery chargers or whatever. :-) ---Joel |